The last batch of arrows I bought; I "float" tested them in the bathtub with some warm soapy water. Ideally, if the arrow's spine is inconsistent it will show in the water. The arrow will roll and I believe the stiffer side rolls to the bottom leaving the weaker side on top. I "believe" you shoot stiffer side down. Its been a while since I did it so I'm a little fuzzy on the details. Hell, I'm not even sure it helped but it did boost confidence, which means ALOT!